Integrated aircraft stairs to allow passengers to board and disembark when the aircraft fuselage door is opened are colloquially known as “airstairs”. Aircraft which include airstairs can thus provide service to many less populated airport environments since a fixed-based gantry platform to allow passengers to board and disembark is not necessarily required. For these reasons, many regional transport and general aviation aircraft are equipped with airstairs as the primary means to allow boarding and disembarking of passenger and aircraft crew members.
In general, most conventional force-balancing mechanisms for airstairs use space-saving torsional bars to accumulate weight energy and power sufficient to provide lift assistance. In this regard, such conventional airstairs will typically employ an actuator/gearbox, which are interconnected by a torsion bar. When the torsion bars are twisted, a large load is accumulated at the ends of the torsion bars which over time results in fatigue failure. When failure occurs, the airstairs may become inoperable resulting in aircraft downtime to allow for repair. As a result, conventional force-balancing mechanisms for airstairs are somewhat problematic due to this continued potential maintenance issue.
What has been needed therefore are space-saving force-balancing mechanisms for loads that are more durable, especially force-balancing mechanisms for loads associated with airstairs for aircraft. It is towards fulfilling such needs for force-balancing mechanisms that the embodiments as disclosed herein are provided.